This disclosure relates generally to the field of image processing. More particularly, but not by way of limitation, this disclosure relates to techniques for improving real-time panoramic photography processing using motion data (e.g., gyroscopic sensor input).
Panoramic photography may be defined generally as a photographic technique for capturing images with elongated fields of view. An image showing a field of view approximating, or greater than, that of the human eye, e.g., about 160° wide by 75° high, is usually termed “panoramic.” Thus, panoramic images generally have an aspect ratio of at least 2:1, meaning that the image is at least twice as wide as it is high (or, conversely, twice as high as it is wide, in the case of vertical panoramic images). In some embodiments, panoramic images may even cover fields of view of up to 360 degrees, i.e., a “full rotation” panoramic image.
There are many challenges associated with taking visually appealing panoramic images. These challenges include photographic problems such as: difficulty in determining appropriate exposure settings caused by differences in lighting conditions across the panoramic scene; blurring across the seams of images caused by motion of objects within the panoramic scene; parallax problems (i.e., problems caused by the apparent displacement or difference in the apparent position of an object in the panoramic scene as the image capture device is panned); properly aligning the various images used to construct the overall panoramic image; blending between the overlapping regions of various images used to construct the overall panoramic image; choosing an image projection correction that does not distort photographically important parts of the panoramic photograph (e.g., rectangular, cylindrical, Mercator); and correcting for perspective changes between subsequently captured images.
Some prior art panoramic photography systems may utilize gyroscopic information to assist in image analysis and registration. As the number of images within a given time period that are aligned to generate a panoramic image increases, however, the computational costs of performing image analysis and registration can become prohibitive. This may be particularly true for image capture devices embedded in handheld electronic devices such as mobile phones, personal data assistants (PDAs), portable music players, digital cameras, as well as laptop and tablet computer systems.